<template>
  <div>
    <button @click="sub">-</button>
    <span>{{ value }}</span>
    <button @click="add">+</button>
  </div>
</template>

<script>
export default {
  name: 'NumberBox',
  props: ['value'],
  methods: {
    sub() { this.$emit('input',this.value -1) },
    add() {this.$emit('input',this.value +1) }
  }
}
</script>

<style lang="less" scoped>
span {
  display: inline-block;
  margin: 0 5px;
}
</style>